The subject matter disclosed herein relates generally to a resistance temperature device (RTD) measurement device. More particularly, the present disclosure related to a RTD measurement device including a switch block to determine wiring setup and wiring failures.
RTD sensors are temperature-sensing devices; therefore, the resistance of an RTD sensor increases with temperature. As seen in FIG. 1, a typical RTD sensor 10 includes 4 wires that may connect to a RTD measurement device 100. However, not all 4 wires are required to utilize the RTD sensor. A first configuration 1 shows a 4-wire configuration, where terminals A, B, C, and D of RTD measurement device 100 are connected to the RTD sensor 10. In a second configuration 2, an exemplary S-wire configuration is shown. In this second configuration 2, only A, B, and C terminals of RTD measurement device 100 are shown as connected. However, it is understood that a 3-wire configuration may include A, B, and D connected; A, C, and D connected; or B, C, and D connected. In a third configuration 3, an exemplary 2-wire configuration is shown. In this third configuration 3, only A and C terminals of RTD measurement device 100 are shown as connected. However, it is understood that a 2-wire configuration may include A and D connected; B and D connected; or B and C connected. In other words, at least one terminal on either side of the RTD sensor 10 must be connected to the RTD measurement device in order to measure the resistance across RTD sensor 10.
Regardless of the type of wiring configuration, at times, there may be poor connections on any of the terminals wires, which can lead to measurement errors.